Serum 25-hydroxyvitamin D level is not associated with glomerular filtration rate in a young healthy population (#398)

Monash Centre for Health Research and Implementation, School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia

Centre for Chronic Disease, Victoria University, Melbourne, Australia

School of Population Health, The University of Auckland, Auckland , New Zealand

Evidence from observational studies indicates a role for vitamin D in kidney function and progression to chronic kidney disease1,2. Findings from animal studies have proposed underlying mechanisms including increased activation of renin-angiotensin system, increased blood pressure, insulin resistance and chronic low-grade inflammation3,4. However, human studies are limited by confounders arising from heterogeneous samples of participants2,5. We examined the relationship between 25(OH)D and estimated glomerular filtration rate (eGFR) in a young healthy drug naive population with normal renal function.

One hundred and twenty one non-diabetic (75g oral glucose tolerance test; OGTT) volunteers (70 males and 51 females), aged 18 to 57 years participated in the study. Median 25(OH)D level was 37 nmol/L and there was no difference between genders. Twenty six participants (21.5%) had 25(OH)D <25 nmol/L, 75 participants (62%) had 25(OH)D of 25-49.99 nmol/L, and 20 participants (16.5%) had 25(OH)D ≥50 nmol/L. In univariate analysis, 25(OH)D was related negatively to percent body fat and 2 hour glucose level post OGTT. Mean (SD) eGFR was 113.08 (14.9) mL/min/1.73 m2, and in multivariate analysis it was related to age, gender, percent body fat and 2 hour glucose level post OGTT, but not to 25(OH)D. Furthermore, there was no relationship between eGFR and 25(OH)D across BMI categories.

Our data suggest that measuring 25(OH)D in young healthy individuals with normal kidney function may not be beneficial in early recognition of kidney disease.